2. Get your wife a paying job if that is possible.
3. Save enough to be able to live off the next 4 years without earning anything.
4. If 3. is not possible, then start something on the side.
5. If savings plus side income gives you runway for 4 years, then you are good to quit and focus fulltime.
6. Dont use your wife's savings to pay the bills. That is just fall back. If you are using up wife's savings/income, then it is right time to start looking for a job.
7. Consider moving into a more comfortable job, which gives you more free time for side hustle.